Case Study

The Gallery House development at Portside East is a luxurious apartment project in Hamilton, Queensland. The project features a 19 and 20 storey building with approximate 169 apartments and 1100m retail space. It is constructed along the riverfront in Hamilton. The building will offer a convenience of easy access to the inner city and stylish waterfront living.

Global Synthetics engaged Geoinventions Consulting Services (GCS) to assess and provide design certification of the proposed Temporary Working Platforms (TWPs) for the piling operations. The scope was to design a sufficiently thick working platform to prevent any punching or bearing failures during the piling operations.

The Problem
As the construction site is adjacent to the Brisbane River, the existing loose to medium dense sand subgrade did not have the required bearing capacity to withstand the proposed 370kPa piling pressures exhibited during operations. In order to achieve the required bearing capacity, GCS designed a platform using a combination of Combigrid® 40/40 geocomposite and Secugrid® 40/40 geogrid.

The Solution

The geogrid component in Combigrid® provides reinforcement whilst the integrated geotextile component provides a positive separation and filtration function. The Combigrid® geocomposite
was placed on top of the weak subgrade and the Secugrid® geogrid layer was placed midway between the 800mm thick platform. By using a geocomposite, GCS provided value engineering by reducing the thickness of the platform compared to conventional working platform designs commonly provided in the industry. This provided material savings and reduced the overall construction timeframe for the construction of these platforms. By using reconstituted Type 2.3 material for the platform reinforce fill, GCS also reduced the need for utilizing processed quarry material and additional transport which further reduced the carbon footprint of this project.

GCS provided the following additional Geotechnical services on the project:
•Construction staging drawings and instructions for efficient construction procedure.
•Experienced on-site geotechnical engineer to inspect platforms and validate the design prior to piling.
•Extension of working platform for access track during travelling